new MD OS v24. SDHC, FAT32

thanks krikzz! problem solved :thumbsup:

 

Eagerly awaiting CD backup cart function, or at least the ability to manually backup and restore the contents of the CD SRAM from the Everdrive.

Do you plan to make the ED MD work like a regular CD RAM backup cart where you can xfer to/from in the CD BIOS or from a CD game directly like an official backup RAM cart, or will it be more like an option in the ED MD toolbox to save/load internal CD SRAM?

I got bored and played Vay to level 99 and now I'm nervous about unplugging the CD unit OH:

 

Does current EDMD board rev and firmware support the ability to act as CD backup ram cart with just an MD OS update? Going to be buying a EDMD too.

 

Nop. Not yet, sadly...
I'm waiting for that too.

Long time ago KRIKzz said it would be implemented with a new OS version one day. I'm still waiting for such day.

 

i never not said that such thing will be implemented by new OS, it just impossible. i said that may be i will made OS update for backup internal CD memory. anyway even if i will made firmware for use edmd ram as backup memory, then it will not give a lot of fun because edmd ram is much more small that regular ram cars have. probalbly games even may not recognize such ram cart

 

I have mentioned this before:-
http://assemblergames.com/forums/showpost.php?p=475030&postcount=4

KRIKzz, even 256Kbit/32KB would be fantastic since the Mega-CD only has 64Kbit/8KB built in RAM, so Everdrive-MD has four times more memory and should give an extra 500+ blocks save space. Original Sega Mega-CD Backup RAM Cart has 1Mbit/128KB SRAM, but that much space would not be necessary with Everdrive-MD if it can backup/restore FRAM to SD card.

Also, all Mega-CD games should support smaller sized backup RAM cart, since support was programmed in by Sega:-
http://segaretro.org/CD_BackUp_RAM_Cart

I know your very busy manufacturing Everdrives, but this would be a really great feature for Everdrive-MD ray: Some Mega-CD games use up all 125 blocks of Mega-CD internal RAM, and "Shining Force CD" actually requires CD Backup RAM Cart to finish the game, so any extra space would be very useful

 

i hope ramcart use 8bit data bus?

 

if it did i take it you could make they add on for it then

 

The SRAM is a Sony CXK58000 131,072 x 8.

 

yes it does, RAM cart is mapped in the $400000-$7FFFFF area and only use D0-D7 (which mean you can disable !CART on cartridge port and then use !CE as chip select, as it will be asserted when software accesses this area)

More infos and schematics:
http://gendev.spritesmind.net/forum...&start=0&sid=bef3035d3b5e057e96ffc3a8174c10b3

 

http://nfggames.com/forum2/index.php?topic=3383.0

 

I already posted the above link and more over a year ago and once more in February, so I guess they dont have enough info to help KRIKzz :shrug:

 

Sorry, KRIKzz. I had misunderstood you...

 

ok, if 32kbyte could be usefull for sega cd, then i will try to do something

 

Just the ability to backup and restore the internal sram to sd would be great, even if Everdrive itself doesn't add RAM.

 

if you can do that i think alot of ppl will like that i no i whould:nod:

 

Thanks KRIKzz

Whilst that would still be useful, there are some Mega-CD games that actually require the Backup RAM Cart. If KRIKzz can make the Everdrive-MD act as a Backup RAM cart then you could always backup internal SRAM saves using the Mega-CD's built-in memory manager.

 

Very useful, for sure!
Thanks a lot!

 

Sorry Krikzz, my problems have suddenly returned! save folder gets recreated in the EDMD folder, everytime I choose select file from the menu.
I am also experiencing problems again and again with OSv29. Sel error 50, error 62, error 110, error 100. Have to keep shutting off and repowering to try again. I've tried formatting fat32 again and again

I've tried two different SD cards: One Sandisk 2gb, and a 4GB sandisk sdhc.

Everything worked perfectly when I had OSv23. I'm giving up on v29 and I am going to go back to v23 (but i'll miss sram support)

I'm just wondering, is my cart defective? can it not accept your OSv29, or SDHC support?

btw my cart has firmware v12 and is rev 2.2

EDIT: Damn, I just formatted my 2gb to fat16 and tried to update OS to v23 from emergency OSv15 (A+B+C boot up) and i get "bios update failed". Then the message "ecc: 0". What is going on with my cart?

 

ecc: 0 error probably because your SD was not formatted by cart tool as need for os15.
i can't remember, but did you tried to enable genny3 mode option?
it looks like your cart have some hardware problems, but in this case os 23 also should work unstable.
anyway, if you would like you could send cart to me for check